The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- @-rules (10 members)
- Administrators (6 members)
- Apple (2 members)
- Apple CSS Extensions (47 members)
- Article management templates (7 members)
- Article stubs (101 members)
- Audio File Types (5 members)
- Bad practices (54 members)
- Basic Concepts (1 member)
- Basic concepts (0 members)
- Best Practices (5 members)
- Block-level elements (26 members)
- BlogListingPage (0 members)
- Blog posts (6 members)
- Browse (17 members)
- Browsers (1 member)
- CSS (42 members)
- CSS Properties (289 members)
- CSS Selectors (8 members)
- Candidates for deletion (1 member)
- Candidates for speedy deletion (0 members)
- Category templates (4 members)
- Code (59 members)
- Community (6 members)
- Companies/Organizations (5 members)
- Content (6 members)
- Copyright (0 members)
- DOM (5 members)
- DOM templates (8 members)
- DOM types (6 members)
- Deprecated (1 member)
- Deprecated elements (1 member)
- Disambiguations (4 members)
- Events (0 members)
- Featured Articles (3 members)
- Files (2 members)
- Firefox Add-ons (2 members)
- Flow content (70 members)
- Form-associated element (1 member)
- Forums (6 members)
- Genealogy pages (14 members)
- General wiki templates (31 members)
- HTML (20 members)
- HTML & CSS templates (2 members)
- HTML DOM (1 member)
- HTML DOM types (15 members)
- HTML Elements (124 members)
- HTML and CSS templates (2 members)
- Help (5 members)
- Help desk (3 members)